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PubMed2004

Comparison of compositions and metabolic activities of fecal microbiotas in young adults and in antibiotic-treated and non-antibiotic-treated elderly subjects.

The colonic microbiota mediates many cellular and molecular events in the host that are important to health. These processes can be affected in the elderly, because in some individuals, the composition and metabolic activities of the microbiota change with age. Detailed characterizations of the major groups of fecal bacteria in healthy young adults, in healthy elderly people, and in hospitalized elderly patients receiving antibiotics were made in this study, together with measurements of their metabolic activities, by analysis of fecal organic acid and ammonia concentrations. The results showed that total anaerobe numbers remained relatively constant in old people; however, individual bacterial genera changed markedly with age. Reductions in numbers of bacteroides and bifidobacteria in both elderly groups were accompanied by reduced species diversity. Bifidobacterial populations in particular showed marked variations in the dominant species, with Bifidobacterium angulatum and Bifidobacterium adolescentis being frequently isolated from the elderly and Bifidobacterium longum, Bifidobacterium catenulatum, Bifidobacterium boum, and Bifidobacterium infantis being detected only from the healthy young volunteers. Reductions in amylolytic activities of bacterial isolates in healthy elderly subjects and reduced short-chain fatty acid concentrations supported these findings, since bifidobacteria and bacteroides are important saccharolytic groups in the colon. Conversely, higher numbers of proteolytic bacteria were observed with feces samples from the antibiotic-treated elderly group, which were also associated with increased proteolytic species diversity (fusobacteria, clostridia, and propionibacteria). Other differences in the intestinal ecosystem in elderly subjects were observed, with alterations in the dominant clostridial species in combination with greater numbers of facultative anaerobes.

Adult↗

PubMed2006

Reduced phase switch capacity and functional adhesin expression of type 1-fimbriated Escherichia coli from immunoglobulin A-deficient individuals.

The mannose-specific adhesin of type 1 fimbriae is the most common adhesin in Escherichia coli. One receptor for this adhesin is the carbohydrate chains of secretory immunoglobulin A (S-IgA), and intestinal E. coli from IgA-deficient individuals has a reduced capacity to adhere to mannose-containing receptors. Here, we investigated the expression of the mannose-specific adhesin and its capacity to switch to the fimbriated phenotype in colonic resident and transient E. coli strains isolated from control (n = 16) and IgA-deficient (n = 17) persons. Resident E. coli strains from IgA-deficient individuals displayed weaker mannose-specific adherence to colonic cells than resident strains from control individuals (21 versus 44 bacteria/cell, P = 0.0009) due to three mechanisms: a lower carriage rate of the fimH gene (90% versus 97%, not significant), more frequent failure to switch on the fim genes (30% versus 6%, P = 0.02), and the reduced adhesive potential of fimH(+) isolates capable of phase switch (26 versus 46 bacteria/cell, P = 0.02). On the other hand, resident strains from IgA-deficient individuals displayed stronger mannose-resistant adherence than resident strains from control individuals (P = 0.04) and transient strains from IgA-deficient individuals (P = 0.01). The presence of S-IgA appears to favor the establishment of E. coli clones which readily express mannose-specific adhesins in the bowel microbiota.

Adhesins, Bacterial↗

PubMed2006

Role of the innate immune system and host-commensal mutualism.

Host organisms live in intimate contact with indigenous microflora. The interactions between the host and commensal microbiota are highly complex and heterogeneous. A growing body of evidence indicates that commensal symbionts provide many benefits to the host physiology, particularly in the gastrointestinal system. The molecular mechanisms of the mutualistic interactions between the host and commensals are largely unknown but can be due either to bioactivity of the commensals or to the reaction of the host immune system to the commensal-derived products. Recent advances in our understanding of the innate immune system allow re-evaluation of some of the older findings regarding the mechanisms of benefits conferred by microflora. Here we review the examples of the benefits of host-commensal interactions that are due to recognition of commensal microbial products by the host innate immune system.

Animals↗

PubMed2006

Contrasting digestive strategies in four New Zealand herbivorous fishes as reflected by carbohydrase activity profiles.

Enzymatic degradation of algal carbohydrates was examined in the New Zealand herbivorous fishes Parma alboscapularis (Pomacentridae), Aplodactylus etheridgii (Aplodactylidae), Girella tricuspidata and G. cyanea (Girellidae). Enzyme extract taken from the anterior gut wall, gut fluid and microbial pellet from sections sampled along the gut were tested for activity against starch, carrageenan, agarose and carboxymethylcellulose. Hydrolysis of starch was greater than for all other substrates tested. Endogenous (host-produced) activity in the anterior gut fluid varied between species in the order G. tricuspidata (7700 units mL(-1))>G. cyanea (2300 units mL(-1))>P. alboscapularis (2000)>A. etheridgii (1400 units mL(-1)) where one unit is equivalent to 1 mug of reducing sugar released per minute. Activity decreased markedly along the gut in all cases, so that at the posterior end of the gut only 0.3-8% of the anterior activity remained in the gut fluid. Enzyme activity against structural carbohydrates was lower than that against starch, and was of exogenous (produced by resident microbiota) origin in all species although the location of activity along the gut differed. The microbial extract of A. etheridgii displayed the highest activity against carrageenan and agarose in all gut sections, reaching maxima of 47 units mL(-1) against carrageenan and 35 units mL(-1) against agarose in the mid-gut microbial extract. Carrageenase and agarase activity in the other three species was <10 units mL(-1) for all gut sections. Results suggest that carrageenan and agarose are potentially important substrates for microbial fermentation, particularly in A. etheridgii, and that there is microbial activity in the mid-gut of this species, rather than primarily in the hind-gut as in other herbivorous species.

Animals↗

PubMed1998

Safety and tolerance of Lactobacillus reuteri supplementation to a population infected with the human immunodeficiency virus.

Probiotic supplementation may provide health benefits, especially for individuals with an underlying disease state that makes them more susceptible to infections. The purpose of this experiment was to evaluate the safety and tolerance of Lactobacillus reuteri ingestion by subjects infected with the human immunodeficiency virus (HIV). Thirty-nine subjects consumed a freeze-dried preparation of L. reuteri or a placebo for 21 days in a double-masked, parallel design experiment. Serum chemistry, haematology, immune profile, urinalysis, physical examination, gastrointestinal tolerance and faecal microbiota data were collected. No clinically significant changes were noted in any of the safety parameters measured. Overall, tolerance was good in both groups. Consumption of L. reuteri tended to increase faecal levels of L. reuteri on days 7, 14 and 21 of treatment feeding (P < 0.06, P < 0.11 and P = 0.05, respectively). However, faecal levels of L. reuteri and total Lactobacillus species were lower than levels previously observed in healthy male adults. Overall, this study documents that L. reuteri may be fed to HIV-positive individuals at 1 x 10(10) colony forming units/day without any clinically significant safety or tolerance problems.

Adult↗

PubMed2003

Evaluation of QIAamp DNA Stool Mini Kit for ecological studies of gut microbiota.

Cell lysis efficiency and the quality of DNA extracts from complex bacterial ecosystems are two major concerns in molecular ecological studies of gut microbiota. In this study, we use PCR-denaturing gradient gel electrophoresis (DGGE) DNA profiling, random cloning and sequence analysis of 16S rRNA genes to compare the QIAamp DNA Stool Mini Kit with the bead beating technique in the preparation of DNA extracts from gut microbiota of pigs. We also developed a washing procedure that can release more than 93% of bacterial cells attached to the gut mucosa. Both the QIAamp kit and bead beating method lysed approximately 95% of bacterial cells. PCR-DGGE DNA profiles of ileal and cecal microbiota from both digesta and mucosa that were generated from the DNA extracts using the two methods were nearly identical. Random cloning and sequence analysis also demonstrated the high quality of DNA extracts using the two methods. Two random clone sets of 16S rRNA genes generated from the DNA extracts had a similar degree of bacterial diversity. Different preparations of DNA extract from a single sample using the QIAamp kit consistently produced similar PCR-DGGE DNA profiles with similarity indexes higher than 99%. Our data suggest the appropriateness of the QIAamp DNA Stool Mini Kit for the studies of gut microbial ecology and the effectiveness of the QIAamp kit in processing multiple samples for cell lysis and DNA extraction.

Animals↗

PubMed2006

Helicobacter bilis triggers persistent immune reactivity to antigens derived from the commensal bacteria in gnotobiotic C3H/HeN mice.

BACKGROUND: Infection with Helicobacter species has been associated with the development of mucosal inflammation and inflammatory bowel disease (IBD) in several mouse models. However, consensus regarding the role of Helicobacter as a model organism to study microbial-induced IBD is confounded by the presence of a complex colonic microbiota. AIM: To investigate the kinetics and inflammatory effects of immune system activation to commensal bacteria following H bilis colonisation in gnotobiotic mice. METHODS: C3H/HeN mice harbouring an altered Schaedler flora (ASF) were selectively colonised with H bilis and host responses were investigated over a 10-week period. Control mice were colonised only with the defined flora (DF). Tissues were analysed for gross/histopathological lesions, and bacterial antigen-specific antibody and T-cell responses. RESULTS: Gnotobiotic mice colonised with H bilis developed mild macroscopic and microscopic lesions of typhlocolitis beginning 3 weeks postinfection. ASF-specific IgG responses were demonstrable within 3 weeks, persisted throughout the 10-week study, and presented as a mixed IgG1:IgG2a profile. Lymphocytes recovered from the mesenteric lymph node of H bilis-colonised mice produced increased levels of interferon gamma, tumour necrosis factor alpha (TNFalpha), interleukin 6 (IL6) and IL12 in response to stimulation with commensal- or H bilis-specific bacterial lysates. In contrast, DF mice not colonised with H bilis did not develop immune responses to their resident flora and remained disease free. CONCLUSIONS: Colonisation of gnotobiotic C3H/HeN mice with H bilis perturbs the host's response to its resident flora and induces progressive immune reactivity to commensal bacteria that contributes to the development of immune-mediated intestinal inflammation.

Animals↗

PubMed2005

Colonization of the cecal mucosa by Helicobacter hepaticus impacts the diversity of the indigenous microbiota.

Establishment of mucosal and/or luminal colonization is the first step in the pathogenesis of many gastrointestinal bacterial pathogens. The pathogen must be able to establish itself in the face of competition from the complex microbial community that is already in place. We used culture-independent methods to monitor the colonization of the cecal mucosa of Helicobacter-free mice following experimental infection with the pathogen Helicobacter hepaticus. Two days after infection, H. hepaticus comprised a minor component of the mucosa-associated microbiota, but within 14 days, it became the dominant member of the community. Colonization of the mucosa by H. hepaticus was associated with a decrease in the overall diversity of the microbial community, in large part due to changes in evenness resulting from the relative dominance of H. hepaticus as a member of the community. Our results demonstrate that invasion of the complex gastrointestinal microbial community by a pathogenic microorganism causes reproducible and significant disturbances in the community structure. The use of non-culture-based methods to monitor these changes should lead to a greater understanding of the ecological principles that govern pathogen invasion and may lead to novel methods for the prevention and control of gastrointestinal pathogens.

Animals↗

PubMed2004

Chemotaxonomic analysis of bacterial populations colonizing the rectal mucosa in patients with ulcerative colitis.

The etiology of ulcerative colitis (UC) is unknown, but evidence links it to bacteria belonging to the normal colonic microbiota. The aims of this study were to characterize bacteria colonizing the rectal epithelium, and to investigate whether significant differences existed in UC. Rectal biopsy specimens were obtained via endoscopy from 9 patients with active colitis and 10 patients without inflammatory bowel disease. Complex bacterial communities colonized the rectal mucosa in all subjects. Overall, 72 bacterial taxa (18 genera) were detected. Twenty species were common to both groups, but only differences in bifidobacteria were statistically significant (P=.005). Peptostreptococci were only detected in patients with UC. Microscopy showed that bacteria in mucosal biofilms often occurred in microcolonies. Interindividual variations in mucosal biofilms made it difficult to assign a role for specific bacteria in UC etiology. However, differences in bifidobacteria and peptostreptococci may implicate these organisms in this disease.

Adult↗

PubMed1977

In situ morphology of the gut microbiota of wood-eating termites [Reticulitermes flavipes (Kollar) and Coptotermes formosanus Shiraki].

Light microscopy and scanning and transmission electron microscopy were used to examine the in situ morphology of the gut microbiota of Reticulitermes flavipes and Caoptotermes formosanus. Laboratory-maintained termites were used and, for R. flavipes, specimens were also prepared immediately after collection from a natural infestation. The latter endeavor enabled a study of different castes and developmental stages of R. flavipes and revealed differences in the microbiota of field versus laboratory specimens. The termite paunch microbiota consisted of an abundance of morphologically diverse bacteria and protozoa. Thirteen bacterial morphotypes in the paunch were described in detail: seven were observed only in R. flavipes, three were observed only in C. formosanus, and three were common to both termite species. The paunch epithelium was densely colonized by bacteria, many of which possessed holdfast elements that secured them tightly to this tissue and to other bacterial cells. Besides bacteria, the protozoan Pyrsonympha vertens adhered to the paunch epithelium of R. flavipes by means of an attachment organelle. Cuplike indentations were present on the paunch epithelial surface and were sites of bacterial aggregation. Ultrastructural features of cups suggested their involvement in ion absorption. In addition to the paunch, the midgut was also colonized by bacteria that were situated between epithelial microvilli. Results suggest that bacteria are an integral part of the gut ecosystem.

Animals↗

PubMed2005

Construction, analysis, and beta-glucanase screening of a bacterial artificial chromosome library from the large-bowel microbiota of mice.

A metagenomic (community genomic) library consisting of 5,760 bacterial artificial chromosome clones was prepared in Escherichia coli DH10B from DNA extracted from the large-bowel microbiota of BALB/c mice. DNA inserts detected in 61 randomly chosen clones averaged 55 kbp (range, 8 to 150 kbp) in size. A functional screen of the library for beta-glucanase activity was conducted using lichenin agar plates and Congo red solution. Three clones with beta-glucanase activity were detected. The inserts of these three clones were sequenced and annotated. Open reading frames (ORF) that encoded putative proteins with identity to glucanolytic enzymes (lichenases and laminarinases) were detected by reference to databases. Other putative genes were detected, some of which might have a role in environmental sensing, nutrient acquisition, or coaggregation. The insert DNA from two clones probably originated from uncultivated bacteria because the ORF had low sequence identity with database entries, but the genes associated with the remaining clone resembled sequences reported in Bacteroides species.

Amino Acid Sequence↗

PubMed1979

Ecological determinants in microbial colonization of the murine gastrointestinal tract: adherence of Torulopsis pintolopesii to epithelial surfaces.

Torulopsis pintolopesii is a yeast indigenous to the gastrointestinal tracts of conventional mice and rats from many colonies. In such natively colonized animals, the organism forms layers on the surface of the epithelium in the secreting portion of the stomach and can be cultured from all areas of the gastrointestinal tract. When given in water or food to germfree mice or specific pathogen-free mice possessing an indigenous microbiota free of yeast, T. pintolopesii also can be cultured from all areas of the tract at population levels ranging from 10(5) to 10(8) cells per g (wet weight). Likewise, as in its native hosts, the organism forms layers on gastric surfaces in the associated animals. The layers form on the secreting surface in both the specific pathogen-free and monoassociated ex-germfree mice. In the latter animal, however, a layer of yeast also forms on the nonsecreting gastric surface. In tests of its capacity to adhere to gastrointestinal surfaces in vitro, the organism adheres to epithelia from all areas of the mouse tract. These findings support an hypothesis that the capacity of T. pintolopesii to adhere to epithelial surfaces may be only one determinant influencing it to form layers on the gastric secreting surface in its native hosts.

Animals↗

PubMed2005

Interaction of mucosal microbiota with the innate immune system.

Organisms live in continuos interaction with their environment; this interaction is of vital importance but at the same time can be life threatening. The largest and most important interface between the organism and its environment is represented by surfaces covered with epithelial cells. Of these surfaces, mucosae comprise in humans approximately 300 m2, and the skin covers approximately 1.8 m2 surface of the human body. Mucosal tissues contain two effector arms of the immune system, innate and adaptive, which operate in synergy. Interaction with commensal bacteria, which outnumber the nucleated cells of our body, occurs physiologically on epithelial surfaces; this interaction could pose the risk of inflammation. The mucosal immune system has developed a complex network of regulatory signalling cascades that is a prerequisite for proper activation but also for a timely inactivation of the pathway. As demonstrated in gnotobiotic animal models of human diseases, impaired regulation of mucosal responses to commensal bacteria plays an important role in the development of several inflammatory and autoimmune diseases.

Animals↗

PubMed2007

16S rRNA gene-based analysis of mucosa-associated bacterial community and phylogeny in the chicken gastrointestinal tracts: from crops to ceca.

Mucosa-associated microbiota from different regions of the gastrointestinal (GI) tract of adult broilers was studied by analysis of 16S rRNA gene sequences. The microbiota mainly comprised Gram-positive bacteria along the GI tract. Fifty-one operational taxonomic units (OTUs) (from 98 clones) were detected in the ceca, as compared with 13 OTUs (from 49 clones) in the crops, 11 OTUs (from 51 clones) in the gizzard, 14 OTUs (from 52 clones) in the duodenum, 12 OTUs (from 50 clones) in the jejunum and nine OTUs (from 50 clones) in the ileum. Ceca were dominantly occupied by clostridia-related sequences (40%) with other abundant sequences being related to Faecalibacterium prausnitzii (14%), Escherichia coli (11%), lactobacilli (7%) and Ruminococcus (6%). Lactobacilli were predominant in the upper GI tract and had the highest diversity in the crop. Both Lactobacillus aviarius and Lactobacillus salivarius were the predominant species among lactobacilli. Candidatus division Arthromitus was also abundant in the jejunum and ileum.

Animals↗

PubMed2005

Mucosal bacteria in ulcerative colitis.

Ulcerative colitis (UC) is an acute and chronic inflammatory bowel disease of unknown aetiology, although bacterial species belonging to the normal colonic microbiota are known to be involved in its initiation and maintenance. Several organisms have been linked to the disease; however, mucosa-associated bacteria are more likely to be involved than their luminal counterparts, due to their close proximity to the host epithelium. Comparative bacteriological analyses were done on rectal biopsies to investigate differences in mucosal bacteria in patients with UC and healthy controls. Complex bacterial communities were found in both groups, with significant reductions in bifidobacterial numbers in UC, which suggested that they might have a protective role in the disease. Accordingly, a therapy for treating UC was designed, with the aim of modifying the mucosal microbiota to increase bifidobacterial colonisation and reduce inflammation. Ranges of mucosal and faecal bifidobacteria were tested for their substrate preferences and their abilities to survive under a variety of environmental conditions. A synbiotic comprising a probiotic (Bifidobacterium longum) isolated from healthy rectal mucosa combined with a prebiotic (oligofructose-enriched inulin - Synergy 1) was developed. The treatment was used in a randomised controlled trial involving eighteen patients with active UC, for a period of 1 month. Rectal biopsies were collected at the beginning and end of the study. Bacteriological analysis and transcription levels of epithelium-related immune markers were assessed. Results demonstrated that short-term synbiotic treatment resulted in increased bifidobacterial colonisation of the rectal mucosa and induced significant reductions in the expression of molecules that control inflammation in active UC.

Adult↗

PubMed2007

Lactobacillus fermentum attenuates the proinflammatory effect of Yersinia enterocolitica on human epithelial cells.

BACKGROUND: Lactobacilli represent a major component of the human microbiota. In this study we investigated whether and how Lactobacillus fermentum inhibits the proinflammatory responses of human epithelial cells on Yersinia enterocolitica infection. METHODS: Human epithelial cells were exposed to Y. enterocolitica pYV(-) or L. fermentum or to both strains, combinations of heat-killed L. fermentum or supernatant of L. fermentum cultures and Y. enterocolitica. The modulation of Y. enterocolitica induced IL-8 levels in the culture supernatants was determined and activation of Rac, p38, and NF-kappaB was investigated. RESULTS: Exposure of human epithelial cells to L. fermentum does not induce NF-kappaB activation and subsequent IL-8 secretion in HeLa cells, whereas Y. enterocolitica induces NF-kappaB activation and high levels of IL-8. Viable L. fermentum, supernatant of L. fermentum cultures, but not heat-killed L. fermentum, inhibited IL-8 secretion of HeLa cells triggered by Y. enterocolitica. Lactobacillus fermentum-exposed HeLa cells showed decreased Rac, p38, and NF-kappaB activation after Y. enterocolitica infection. Treatment of L. fermentum supernatants with phospholipase C abolished the inhibitory effect, indicating that a secreted phospholipid mediates the antiinflammatory properties of L. fermentum. Adhesion to or invasion of Y. enterocolitica into epithelial cells was not altered by coincubation with L. fermentum. CONCLUSION: Our results lead to the conclusion that L. fermentum inhibits the Y. enterocolitica-induced IL-8 production by a possibly secreted phospholipid of <10 kDa molecular weight. These data suggest that L. fermentum may have probiotic properties modulating intestinal inflammatory responses and might offer new therapeutic strategies in the treatment of intestinal inflammatory diseases.

Bacterial Adhesion↗

PubMed2004

In vitro metabolism of anthocyanins by human gut microflora.

BACKGROUND: Only a small part of the dietary anthocyanins are absorbed. Thus large amounts of the ingested compounds are likely to enter the colon. In vitro and in vivo studies have shown that colonic bacteria transform various flavonoids to smaller phenolic acids. However, there is very little information on bacterial transformations of anthocyanins. AIM OF THE STUDY: was to explore if anthocyanin glycosides were deglycosylated,whether the resulting aglycones were degraded further to smaller phenolic compounds by colonic bacteria, and to characterise metabolites. METHODS: Isolated cyanidin-3-glucoside and -rutinoside were fermented in vitro using human faecal microbiota as an inoculum. Metabolites were analysed and characterised by HPLC-DAS and LC-MS. They were identified by comparing their characteristics with those of available standards, and semi-quantified using the amount of substrate analysed from samples at initial timepoint. RESULTS: Cyanidin-3-glucoside and cyanidin aglycone could be identified as intermediary metabolites of cyanidin-3-rutinoside. At early timepoints (before 2 h), the formation of protocatechuic acid as a major metabolite for both cyanidin glycosides and detection of lower molecular weight metabolites show that anthocyanins were converted by gut microflora. Furthermore, reconjugation of the aglycone with other groups, non-typical for dietary anthocyanins, was evident at the later (after 2h) timepoints. CONCLUSION: Bacterial metabolism of anthocyanins involves the cleavage of glycosidic linkages and breakdown of the anthocyanidin heterocycle.

Anthocyanins↗

PubMed1995

Roles of oxygen and the intestinal microflora in the metabolism of lignin-derived phenylpropanoids and other monoaromatic compounds by termites.

Prompted by our limited understanding of the degradation of lignin and lignin-derived aromatic metabolites in termites, we studied the metabolism of monoaromatic model compounds by termites and their gut microflora. Feeding trials performed with [ring-U-(sup14)C]benzoic acid and [ring-U-(sup14)C]cinnamic acid revealed the general ability of termites of the major feeding guilds (wood and soil feeders and fungus cultivators) to mineralize the aromatic nucleus. Up to 70% of the radioactive label was released as (sup14)CO(inf2); the remainder was more or less equally distributed among termite bodies, gut contents, and feces. Gut homogenates of the wood-feeding termites Nasutitermes lujae (Wasmann) and Reticulitermes flavipes (Kollar) mineralized ring-labeled benzoic or cinnamic acid only if oxygen was present. In the absence of oxygen, benzoate was not attacked, and cinnamate was only reduced to phenylpropionate. Similar results were obtained with other, nonlabeled lignin-related phenylpropanoids (ferulic, 3,4-dihydroxycinnamic, and 4-hydroxycinnamic acids), whose ring moieties underwent degradation only if oxygen was present. Under anoxic conditions, the substrates were merely modified (by side chain reduction and demethylation), and this modification occurred at the same time as a net accumulation of phenylpropanoids formed endogenously in the gut homogenate, a phenomenon not observed under oxic conditions. Enumeration by the most-probable-number technique revealed that each N. lujae gut contained about 10(sup5) bacteria that were capable of completely mineralizing aromatic substrates in the presence of oxygen (about 10(sup8) bacteria per ml). In the absence of oxygen, small numbers of ring-modifying microorganisms were found (<50 bacteria per gut), but none of these microorganisms were capable of ring cleavage. Similar results were obtained with gut homogenates of R. flavipes, except that a larger number of anaerobic ring-modifying microorganisms was present (>5 x 10(sup3) bacteria per gut). Neither inclusion of potential cosubstrates (H(inf2), pyruvate, lactate) nor inclusion of hydrogenotrophic partner organisms resulted in anoxic ring cleavage in most-probable-number tubes prepared with gut homogenates of either termite. The oxygen dependence of aromatic ring cleavage by the termite gut microbiota is consistent with the presence, and uptake by microbes, of O(inf2) in the peripheral region of otherwise anoxic gut lumina (as reported in the accompanying paper [A. Brune, D. Emerson, and J. A. Breznak, Appl. Environ. Microbiol. 61:2681-2687, 1995]). Taken together, our results indicate that microbial degradation of plant aromatic compounds can occur in termite guts and may contribute to the carbon and energy requirement of the host.

Journal Article↗